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The Catholic Diocese of St. Petersburg recently reminded the faithful of the Week of Prayer for Christian Unity, which kicked off earlier this month.

The diocese used its Facebook page to invite all Christians to observe the octave of prayer in the centuries-long annual observances.

"January 18-25 is the annual observance of the #WeekofPrayerforChristianUnity," the diocese said in a Facebook post on Jan. 16. "We invite you to join us and Christians everywhere in praying that we may all be one, joining our prayer with that of our Lord, Jesus Christ. #courageouslyliving"

The post included an image of people joining hands with the prayer: "God of all, We pray as one, that we may be one, just as the Lord Jesus prayed we may be one in Him. Your son Jesus compels us to be reconciled to one another. May our spirits be joined to your Holy Spirit, that we may witness to the visible unity of your Church. May we all recognize that we are truly one with you, Father, Son and Holy Spirit, and grow together in peace. We ask this in the name of Jesus our Lord. Amen."

First observed in 1908 by Franciscan Friars and Sisters of the Atonement in New York, the Week of Prayer for Christian Unity grew into a worldwide observance in many nations and among millions of Christians who participate in an octave of prayer for unity. In the northern hemisphere, the traditional Week of Prayer is Jan. 18-25.

This year, the Middle East Council of Churches proposed a verse from the Gospel of Matthew, "We saw the star in the East, and we came to worship Him." The verse highlights the Eastern Church tradition of celebrating the Epiphany in connection to the Baptism of Christ and the unity of all Christians through baptism.

On the evening before this year's Week of Prayer began, Pope Francis delivered an address to the Ecumenical Delegation from Finland, tying this year’s theme to the theme of the Synod, "journeying together."

Last year's theme was from the Gospel of John, selected by the Monastic Community of Grandchamp in Switzerland: "Abide in my love ... You shall bear much fruit."